Harike Wetland spread over an area of 41 sq.km is located at the confluence of two majestic rivers - Sutlej and Beas in Punjab. Situated at 31°13'North Latitude and 75° 12'East Longitude, it is one of the largest fresh water wetlands in northern India. This strategic habitat has been facing enormous problem of excessive growth of water hyacinth that had covered more than 70% of the lake area. Thus depriving the migratory birds from free access to this unique habitat. Punjab State Council for Science and Technology through various implementing agencies has been taking priority based conservation and management programmes including control of water hyacinth since 1987-88. For control of this obnoxious weed an integrated approach involving three methods namely manual, mechanical and biological have been adopted. Chemical method has not been used because of its environmental implications. Biological method though was started in 1993 have been slow. It has been considered that perhaps low winter temperature and critical pollution levels during different seasons in this lake could have been a cause of low success of Biological agents. Of the two weevil species namely Neochetina eichhomiae and N.bruchi only the latter could successfully establish itself in this wetland which otherwise is not considered that virulent against water hyacinth as N eichhorniae is. Weevil release operations were intensified in the weed infested catchment areas to check inflow of this weed from upper reaches of source tributaries. During 2000-2001 Govt. of Punjab solicited the help of Army for control of water hyacinth. Application of a combination of mechanical systems like motorised winches, rakers, and conveyor belts coupled with dynamic booms have yielded spectacular results. About 8 sq.km area densely covered with water hyacinth was cleared in record time of four months. Surprisingly the water quality showed some improvements and the flux of migratory birds enhanced to almost double during the project as compared to the previous years. The technology is being replicated in other wetlands as well. This unique experience and mechanism evolved for tackling water hyacinth needs to be shared with other wetland managers for conservation and protection of wetlands. Details shall be discussed.

Punjab State Council for Science and Technology,
Sector 26, Chandigarh, India;
E-mail: ssladhar@excite.com